Simplify toolbar separators

The division is kind of logical, it might make sense for the view
to create the center widget, then we'd get rid of some recently added
GObject boilerplate.

Only make_separator() is kind of annoying.

fastiv.c

@@ -54,6 +54,8 @@ exit_fatal(const gchar *format, ...)
 
 // --- Main --------------------------------------------------------------------
 
+// TODO(p): See if it's possible to give separators room to shrink
+// by some minor amount of pixels, margin-wise.
 // TODO(p): Add a toggle for a checkerboard background.
 // TODO(p): Implement commented-out actions.
 #define B make_toolbar_button
@@ -62,23 +64,23 @@ exit_fatal(const gchar *format, ...)
 	XX(BROWSE,        B("view-grid-symbolic", "Browse")) \
 	XX(FILE_PREVIOUS, B("go-previous-symbolic", "Previous file")) \
 	XX(FILE_NEXT,     B("go-next-symbolic", "Next file")) \
-	XX(S1,            make_separator()) \
+	XX(S1,            gtk_separator_new(GTK_ORIENTATION_HORIZONTAL)) \
 	XX(PAGE_FIRST,    B("go-top-symbolic", "First page")) \
 	XX(PAGE_PREVIOUS, B("go-up-symbolic", "Previous page")) \
 	XX(PAGE_NEXT,     B("go-down-symbolic", "Next page")) \
 	XX(PAGE_LAST,     B("go-bottom-symbolic", "Last page")) \
-	XX(S2,            make_separator()) \
+	XX(S2,            gtk_separator_new(GTK_ORIENTATION_HORIZONTAL)) \
 	XX(SKIP_BACK,     B("media-skip-backward-symbolic", "Rewind playback")) \
 	XX(SEEK_BACK,     B("media-seek-backward-symbolic", "Previous frame")) \
 	XX(PLAY_PAUSE,    B("media-playback-start-symbolic", "Pause")) \
 	XX(SEEK_FORWARD,  B("media-seek-forward-symbolic", "Next frame")) \
-	XX(S3,            make_separator()) \
+	XX(S3,            gtk_separator_new(GTK_ORIENTATION_HORIZONTAL)) \
 	XX(PLUS,          B("zoom-in-symbolic", "Zoom in")) \
 	XX(SCALE,         gtk_label_new("")) \
 	XX(MINUS,         B("zoom-out-symbolic", "Zoom out")) \
 	XX(ONE,           B("zoom-original-symbolic", "Original size")) \
 	XX(FIT,           T("zoom-fit-best-symbolic", "Scale to fit")) \
-	XX(S4,            make_separator()) \
+	XX(S4,            gtk_separator_new(GTK_ORIENTATION_HORIZONTAL)) \
 	/* XX(PIN,        B("view-pin-symbolic", "Keep view configuration")) */ \
 	/* Or perhaps "blur-symbolic", also in the extended set. */ \
 	XX(SMOOTH,        T("blend-tool-symbolic", "Smooth scaling")) \
@@ -86,11 +88,11 @@ exit_fatal(const gchar *format, ...)
 	XX(SAVE,          B("document-save-as-symbolic", "Save as...")) \
 	XX(PRINT,         B("document-print-symbolic", "Print...")) \
 	/* XX(INFO,       B("info-symbolic", "Information")) */ \
-	XX(S5,            make_separator()) \
+	XX(S5,            gtk_separator_new(GTK_ORIENTATION_HORIZONTAL)) \
 	XX(LEFT,          B("object-rotate-left-symbolic", "Rotate left")) \
 	XX(MIRROR,        B("object-flip-horizontal-symbolic", "Mirror")) \
 	XX(RIGHT,         B("object-rotate-right-symbolic", "Rotate right")) \
-	XX(S6,            make_separator()) \
+	XX(S6,            gtk_separator_new(GTK_ORIENTATION_HORIZONTAL)) \
 	/* We are YouTube. */ \
 	XX(FULLSCREEN,    B("view-fullscreen-symbolic", "Fullscreen"))
 
@@ -723,17 +725,6 @@ make_toolbar_toggle(const gchar *symbolic, const gchar *tooltip)
 	return button;
 }
 
-static GtkWidget *
-make_separator(void)
-{
-	// TODO(p): See if it's possible to give the separator room to shrink
-	// by some minor amount of pixels, margin-wise.
-	GtkWidget *separator = gtk_separator_new(GTK_ORIENTATION_HORIZONTAL);
-	gtk_widget_set_margin_start(separator, 10);
-	gtk_widget_set_margin_end(separator, 10);
-	return separator;
-}
-
 static void
 on_view_actions_changed(void)
 {
@@ -873,9 +864,19 @@ make_view_toolbar(void)
 
 	// GtkStatusBar solves a problem we do not have here.
 	GtkWidget *view_toolbar = gtk_box_new(GTK_ORIENTATION_HORIZONTAL, 0);
+	gtk_widget_set_name(view_toolbar, "toolbar");
 	GtkBox *box = GTK_BOX(view_toolbar);
-	for (int i = 0; i < TOOLBAR_COUNT; i++)
+
+	// Exploring different versions of awkward layouts.
+	for (int i = 0; i <= TOOLBAR_S1; i++)
 		gtk_box_pack_start(box, g.toolbar[i], FALSE, FALSE, 0);
+	for (int i = TOOLBAR_COUNT; --i >= TOOLBAR_S6; )
+		gtk_box_pack_end(box, g.toolbar[i], FALSE, FALSE, 0);
+
+	GtkWidget *center = gtk_box_new(GTK_ORIENTATION_HORIZONTAL, 0);
+	for (int i = TOOLBAR_S1; ++i < TOOLBAR_S6; )
+		gtk_box_pack_start(GTK_BOX(center), g.toolbar[i], FALSE, FALSE, 0);
+	gtk_box_set_center_widget(box, center);
 
 	toolbar_connect(TOOLBAR_BROWSE,        G_CALLBACK(switch_to_browser));
 	toolbar_connect(TOOLBAR_FILE_PREVIOUS, G_CALLBACK(on_previous));
@@ -971,17 +972,16 @@ main(int argc, char *argv[])
 
 	// This is incredibly broken https://stackoverflow.com/a/51054396/76313
 	// thus resolving the problem using overlaps.
-	// XXX: button.flat is too generic, it's only for the view toolbar.
-	// XXX: Similarly, box > separator.horizontal is a temporary hack.
-	// Consider using a #name or a .class here, possibly for a parent widget.
 	const char *style = "@define-color fiv-tile #3c3c3c; \
 		fiv-view, fiv-browser { background: @content_view_bg; } \
 		placessidebar.fiv .toolbar { padding: 2px 6px; } \
 		placessidebar.fiv box > separator { margin: 4px 0; } \
-		button.flat { padding-left: 0; padding-right: 0 } \
-		box > separator.horizontal { \
+		#toolbar button { padding-left: 0; padding-right: 0; } \
+		#toolbar > button:first-child { padding-left: 4px; } \
+		#toolbar > button:last-child { padding-right: 4px; } \
+		#toolbar separator { \
 			background: mix(@insensitive_fg_color, \
-				@insensitive_bg_color, 0.4); margin: 6px 0; \
+				@insensitive_bg_color, 0.4); margin: 6px 10px; \
 		} \
 		fiv-browser { padding: 5px; } \
 		fiv-browser.item { \
@@ -1019,11 +1019,9 @@ main(int argc, char *argv[])
 	g_object_set(gtk_settings_get_default(),
 		"gtk-application-prefer-dark-theme", TRUE, NULL);
 
-	GtkWidget *view_toolbar = make_view_toolbar();
-	gtk_widget_set_halign(view_toolbar, GTK_ALIGN_CENTER);
-
 	// Need to put the toolbar at the top, because of the horizontal scrollbar.
 	g.view_box = gtk_box_new(GTK_ORIENTATION_VERTICAL, 0);
+	GtkWidget *view_toolbar = make_view_toolbar();
 	gtk_box_pack_start(GTK_BOX(g.view_box), view_toolbar, FALSE, FALSE, 0);
 	gtk_box_pack_start(GTK_BOX(g.view_box),
 		gtk_separator_new(GTK_ORIENTATION_VERTICAL), FALSE, FALSE, 0);